Tetracyclines drugs

Tetracyclines are produced by various Streptomyces strains and are extensively applied in human and veterinary medicine. They display a broad spectrum of antimicrobial activity in combination with low toxicity and can be applied orally. The most commonly prescribed tetracycline drugs are tetracycline itself and oxytetracycline, an oxygenated derivative, which are directly isolated from fermentation liquors, and doxycycline whose partial synthesis from oxy-... 

Most of the methods in which the paper is treated with a chelating agent are capable of showing a separation of some of the tetracycline drugs from each other and from their respective epimeric forms. They are also capable of revealing the presence of common degradation compounds of these drugs. 

Others have described modifications of these methods for various purposes. Hiscox (82) suggested the direct spec-trophotometric assay of CTC in either acid or alkaline solution at various UV wavelengths. The possible contamination of CTC with other tetracycline drugs was addressed by Chicearelli et... 

Zhanel GG Homenuik K, Nichol K, Noreddin A, Vercaigne L, Embil J, Gin A, Karlowsky JA, Hoban DJ. (2004) The glycylcyclines A comparative review with the tetracyclines. Drugs 64 63-88. 

Photosensitivity Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines. Advise patients who are apt to be exposed to direct sunlight or ultraviolet light that this reaction can occur with tetracycline drugs, and discontinue treatment at the first evidence of skin erythema. 

A photosensitivity reaction, which manifests as an exaggerated simburn, is common in patients receiving any tetracycline drug. Hypersensitivity reactions to tetracyclines including anaphylaxis, urticaria, periorbital edema, and morbilliform rashes can occur but are uncommon. 

Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs 1976 11 45-54. 

Mack, G. D. and Ashworth, R. B. A high performance liquid chromatographic system for the analysis of tetracycline drug standards, analogs, degradation products and other impurities. J. Chromatogr. Sci. 16 93-101, 1978. 

Protein synthesis inhibition results from reversible binding of the tetracycline drugs to the 30S ribosomal subunit. This in turn prevents the attachment of aminoacyl-fRNAs to the acceptor site of the ribosomal structure (Fig. 6-17). The ribosomal mRNA complex is thus effectively precluded from initiating protein synthesis. Tetracyclines do not interfere with actual peptide bond formation, nor with the translocation process. In vitro studies with 70S ribosomes using photoaffinity techniques demonstrate binding to the 4S and 18S protein components of the 30S subunits. It is likely that these are the actual binding sites. 

Which tetracycline drug is useful for meningococcal prophylaxis ... 

Because of their chelating action, tetracycline drugs are inactivated in the patient s bowel by any dietary calcium or magnesium ions, whether from milk or from antacid medication. Through such mishaps, many patients have lost the potential benefit of these antibiotics. Tetracyclines are usually given orally. Tetracycline, itself, is still much prescribed, but there are also lower-dose forms available demeclocycline and methacycline, and a sub-class of these which require less frequent dosing doxycycline and minocycline. 

Discuss the uses, general drug action, adverse reactions, contraindications, precautions, and interactions of the tetracyclines, macrolides, and... 

SUMMARY DRUG TABLE TETRACYCLINES, MACROLIDES AND LINCOSAMIDES... 

The tetracyclines are contraindicated if the patient is known to be hypersensitive to any of the tetracyclines. Tetracyclines also are contraindicated during pregnancy because of die possibility of toxic effects to the developing fetus. The tetracyclines are classified Pregnancy Category D drag. These drug also are contraindicated... 

Ms. Jbnes has been prescribed tetracycline. She works nights and is home sleeping during the day. To decrease the possibility of noncompliance with the treatment regimen, discuss how and what you would teach Ms. Jbnes about her drug regimen. 

Doxycycline (Vibramycin) is an antibiotic belonging to die tetracycline group of antibiotics. The adverse reactions associated with this drug are discussed in Chapter 9 and include photosensitivity, anorexia, nausea, and vomiting. 

There is an increased risk of toxicity of MTX when administered with the NSAIDs, salicylates, oral antidiabetic drugs, phenytoin, tetracycline, and probenecid. There is an additive bone marrow depressant effect when administered with other drug known to depress the bone marrow or with radiation therapy. There is an increased risk for nephrotoxicity when MTX is administered with other drug that cause nephrotoxicity. When penicillamine is administered with digoxin, decreased blood levels of digoxin may occur. There is a decreased absorption of penicillamine when the dmg is administered with food, iron preparations, and antacids. 

The effects of warfarin may increase when administered with acetaminophen, NSAIDs, beta blockers, disulfiram, isoniazid, chloral hydrate, loop diuretics, aminoglycosides, cimetidine, tetracyclines, and cephalosporins. Oral contraceptives, ascorbic acid, barbiturates, diuretics, and vitamin K decrease the effects of warfarin. Because die effects of warfarin are influenced by many drugp, die patient must notify die nurse or die primary healdi care provider when taking a new drug or discontinuing... 

Oral administration of bicarbonate may decrease the absorption of ketoconazole. Increased blood levels of quinidine, flecainide, or sympatiiomimetics may occur when these agents are administered with bicarbonate There is an increased risk of crystalluria when bicarbonate is administered with the fluoroquinolones. Fbssible decreased effects of lithium, methotrexate, chlorpropamide, salicylates, and tetracyclines may occur when these drag s are administered with sodium bicarbonate. Sodium bicarbonate is not administered within 2 hours of enteric-coated drugs the protective enteric coating may disintegrate before the drug reaches the intestine. 

The differential diagnosis for PIH includes the following fixed drug eruption, systemic drug-induced hyperpigmentation, macular amyloid, ashy dermatosis, melasma, and tinea versicolor. Medications such as tetracyclines, antimalarial drugs, arsenic, bleomycin, and doxorubicin can result in hyperpigmentation of the skin. 

Discovery of Kanamycin, and Establishment oflMC. Chloramphenicol, chlor- and oxy-tetracyclines, and pyridomycin (H. Umezawa, 1967) were active, in in vitro experiments, against strains of tuberculosis, but these drugs, in contrast to streptomycin, were clinically inactive. H. Umezawa... 

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